I. Field of the Invention
This invention relates to cutting tools and particularly to rotatable cutting tools of the having a tool body with recesses for receiving replaceable inserts with cutting edges. More particularly, this invention relates to improved insert retaining means for milling cutters wherein inserts are releasably mounted to the periphery of a tool body.
II. Description of Related Art
Known milling cutters comprising replaceable inserts use various means for mounting the inserts to the tool body. Examples of milling cutters wherein inserts are mounted to the tool body using screws are illustrated in U.S. Pat. No. 4,934,880. Examples of milling cutters wherein inserts are held to the tool body by releasable clamps are illustrated in U.S. Pat. No. 3,588,977. While such known tools provide secure mounting of replaceable inserts to the tool body, use of individual screws or clamps for each replaceable insert has the inherent disadvantage of requiring independent release and adjustment of each insert mounting device for each insert to be replaced. Hence, there is a need for improved mounting means for such tools that simplify release and remounting of replaceable inserts.
A cutting tool with an insert retaining means wherein all inserts are released and retained by a single tool element is illustrated in U.S. Pat. No. 5,662,436. In this tool, a star shaped holding member is mounted to a base having seats for plural replaceable inserts. The radial protrusions of the holding member are shaped to interfit in gaps between the replaceable inserts and abutments of the base. With inserts supported on pins on the base member, the holding member is distorted by a clamping nut to cause the radial protrusions to fill the gaps, thereby securing the inserts in place on the base member. As illustrated by FIG. 9 of U.S. Pat. No. 5,662,436, release and removal of inserts from the base member requires separation of the base and the holding member. Hence, there is a continuing need to further improve tools to simplify release and remounting of replaceable inserts.
It is an object of the present invention to provide a rotatable cutting tool wherein plural replaceable inserts are retained in a cutting portion thereof, each replaceable insert providing at least one cutting edge, the cutting tool comprising insert clamping means for retaining an insert in each recess and operative concurrently for all inserts using a single adjusting means.
It is a further object of the present invention to provide a rotatable cutting tool comprising an insert mounting disk having at the periphery thereof plural insert receiving recesses, the insert mounting disk being removeably mounted to a shank portion of the cutting tool, and insert clamping means for releasably retaining a replaceable insert in each recess by exerting a compressive force transverse to each insert, the compressive force for all inserts being established concurrently by a single clamp adjusting means.
It is a still further object of the present invention to provide a rotatable cutting tool comprising an insert mounting disk removeably mounted to a shank portion of the tool, the mounting disk having plural peripheral insert receiving recesses, a central bore, at least one radial groove connecting the central bore and each recess and having a concave central portion surrounding the central bore, the tool comprising clamping means comprising a clamping screw for elastically deforming the concavity of the disk against a face of the tool shank portion whereby opposing portions of each recess exert compressive forces on an insert therebetween.
Further objects and advantages of the invention shall be made apparent from the accompanying drawings and the following description thereof.
In accordance with the aforesaid objects the present invention provides a rotatable cutting tool having a shank portion for mounting to a tool driving device and a cutting portion in which are retained plural replaceable cutting inserts, each insert having at least one cutting edge. The shank portion includes a mounting face for receiving a cutting portion of the tool. The cutting portion comprises an insert mounting disk having plural recesses at the periphery thereof for receiving the replaceable inserts. Each recess provides at least one seating surface for an insert, and includes opposing face portions between which an insert is releasably retained. The disk includes a central bore and plural radial grooves open to a first side of the disk, at least one radial groove connecting the central bore and each insert receiving recess. A concave central portion surrounds the central bore on a second side of the disk. The disk is mounted to the cutting tool shank with an adjusting means having a shaft portion passing through the central bore of the disk. The adjusting means is used to elastically deform the concavity of the disk. With replaceable inserts in place, elastic deformation of the disk to flatten the concavity concurrently builds insert retaining compressive forces by opposing faces of each insert receiving recess; relaxation of the deformation to restore the concavity concurrently relieves the retaining forces exerted by the opposing faces of each insert receiving recess, permitting release of the inserts.